Board Not Detected

Hello everyone, I'm a little new in the arduino forum, but not in the basic use of the IDE, boards and how to upload the sketchs. The same trouble has happened to me, suddenly when modifying some ports of my initial sketch the board does not detect by my PC. The board is an original Arduino UNO, where the LEDs of ON i of the LED of the board are on. But in the IDE I can not select the serial port because the lash is disabled. I have tried to assign the driver again, I also do not see any unknown device in device manager, even to manually add the hardware in windows device manager and I always end up saying "you can not start the board (Code 10)."

I hope someone can help me.

Thank you very much